The present invention relates to an apparatus for reproducing signals, for example video and/or audio signals, from a disc, and more particularly to an apparatus including a means for holding a disc within a casing and for, when necessary, releasing the disc so that the disc may be taken out of the casing.
In general, a video disc is mounted on a turntable of an apparatus for reproducing PCM signals by a reproducing stylus coming in contact with the video disc to reproduce PCM signals recorded on the video disc. These signals consist of a video signal and an audio signal and are recorded at an extremely high packing density in accordance with the PCM (pulse code modulation) recording system, etc. When the surface of the video disc is contaminated by dust and fingerprints, reproduction is degraded and noise is mixed with the reproduced signals. Various apparatuses have been developed comprising a means for mounting and dismounting a video disc on the turntable without it being touched by the hand.
The outer periphery of the video disc is surrounded by a holding frame which is locked in a casing with one side remaining open; thus, the video disc is stored in the casing. The video disc in this condition is inserted in the apparatus for producing PCM signals from one side. When insertion is completed, the video disc surrounded by the holding frame is held in the apparatus for producing PCM signals, and the holding frame is unlocked from the casing. When the casing is pulled out of the apparatus for reproducing PCM signals, the video disc with the holding frame is automatically removed from the open side of the casing, whereby the video disc and the holding frame remain inside the apparatus for reproducing PCM signals. The casing is thus empty. In this condition, reproduction is initiated. When the reproduction is completed, the empty casing is inserted from the open side into the apparatus. The video disc held by the holding frame is stored in the casing from the open side, and the holding frame is locked in the casing. When the casing is withdrawn from the apparatus, the video disc with the holding frame in the casing is removed from the apparatus.
For accomplishing the above-mentioned operation, when the casing in which the video disc is surrounded by the holding frame which is in turn locked by the casing is inserted in the apparatus for reproducing PCM signals, holding means is required for unlocking the holding frame from the casing and for holding the holding frame to the apparatus and, after reproduction is completed and when the empty casing is inserted to the apparatus in which the video disc is mounted, for releasing engagement of the holding frame with the apparatus and for locking the holding frame to the casing. Conventionally, such a holding means has been proposed. However, it has a complex structure and requires many component parts. With this holding means, the holding frame may not be smoothly locked and erratic operation often occurs. Further, a great force is required for inserting the casing into the apparatus, so those who are not strong enough to insert the case cannot conveniently use the holding means.